Dosifilm PVG was a new radiochromic film dosimeter composed of matrix material polyvinyl butyral (PVB), leuco malachite green (LMG) and additive halogenated organic compounds (RX), etc. The control of the dose range on PVG dosifilm was examined. The addition of halogenated compounds played an important role in the radiation reaction of LMG beyond the concentration of LMG. Bromide was more effective than chloride in this system, the oxidative species were X•and X,2,-,. PVB with N-bromosuccinimide (NBS) induced the oxidation of LMG before irradiation. The reaction mechanism of PVG was discussed. Different linear ranges of radiation response on PVG dosifilm could be controlled by alternating the relative concentrations of halogenated compounds and LMG.